The present invention provides an intravenous fluid supply device that periodically extrudes a predetermined amount of an infusion fluid at regular time intervals in a manipulated manner, regardless of the position of an infusion bag, enables round-the-clock real-time visual checking for normal supply of an infusion fluid without using a conventional drop pipette, guarantees safety by activating an alarm when air is included in an infusion fluid or when the fluid is injected excessively or insufficiently, and offers convenience of being portable by having compactness and realizing lower-current consumption than the conventional art.
An infusion fluid has to be administered at a constant rate at regular time intervals.
First, it is known that an infusion fluid can be stably administered without blood backflow when an infusion bag is placed to be about 80 cm higher than a patient's heart because an appropriate pressure for injection of an infusion fluid can be maintained at that height. To this end, a hanger is typically used to maintain the height of an infusion bag. When an infusion fluid is injected based on the gravity, a patient or nurse has to be always careful that the height of an infusion bag is adequate. For this reason, when a patent moves, the patient has to carry a hanger with an infusion bag hung on it or a nurse has to accompany the patient, raising the infusion bag to an adequate height.
Alternatively, a pressing means for obtaining an adequate pressure can be used. For example, there is an infusion fluid injection method that injects an infusion fluid by indirectly pressing an infusion fluid storage container using expanding force of compressed air or highly pressurized gas that can press an infusion bag, or using a gas that is diffused into a piston at a predetermined speed.
Further alternatively, it is possible to press an infusion bag by pressing a pressing plate using recovery force of a coil spring or screwing of a motor.
Yet further alternatively, injection of an infusion fluid can be performed by pressing an infusion bag by slowly winding an infusion bag around a roller using recovery force of a clockwork device or rotation of a motor.
Each of these methods requires use an additional complex device for pressing the infusion bag.
Second, a peristaltic pump or a roller-type pump is generally used to electronically control an appropriate injection speed.
A peristaltic pump sequentially operates pressing fingers by driving cam arrays that are distanced from each other by a predetermined angle, thereby inducing a linear wave motion. This linear wave motion moves a liquid contained in a tube, thereby extruding the liquid.
A roller-type pump performs injection of an infusion fluid by moving a liquid contained in a tube in such a manner that a plurality of rollers rotate and internally touch the surface of a cylindrical tube to discharge the liquid. According to the injection method using pumps, an infusion fluid is supplied by a motor. Accordingly, the motor needs to be continuously activated at a controlled predetermined speed. When it is necessary to inject an infusion fluid for a long period, an activation time of the motor is long, which results in consumption of a large amount of current. Therefore, the injection method using a pump is an inefficient injection method. Furthermore, because of consumption of a large amount of current, a large battery has to be used. Therefore, an infusion fluid supply device employing this method is inevitably large and heavy, and thus is not portable.